Refractive surgery is the correction of visual defects – such as myopia, hyperopia, and astigmatism – with surgery. The different surgical methods include the implantation of multifocal and accommodative intraocular lenses with LASIK, LASEK, PRK, Epi-LASIK, SMILE, Intacs, and CK. Laser refractive surgery is based on removing certain amounts of cornea tissue from certain locations by dissolving carbon bonds between cornea molecules, thus sculpting the cornea. Excimer laser makes it possible to correct myopia up to 10 Diopters, hyperopia up to 5 Diopters, and astigmatism up to 5 Diopters. The outcome of the treatment may be different for every person.
This method includes using a computer-controlled Femtosecond (quadrillionth of a second) laser to create the flap that is required for refractive surgery. The laser creates the flap in the cornea by creating a layer of carbon dioxide and water that is 2-3 microns-thick with 15000 laser pulses per second. Intralase eliminates almost all complications associated with flap creation by removing the need for a scalpel. The flap creation step, which has traditionally been done with the help of a surgical scalpel, has been replaced by a laser with an accuracy measured in microns. This technology has made it possible for the initial step of LASIK surgery that is associated with the most complications to be performed with a computer-controlled laser. Intralase will create the flap according to the predetermined location, diameter, and thickness. Intralase improves surgery outcomes by personalizing flap creation for every patient. It provides stable and healthy results. It is also possible to operate patients whose eyes are not suitable for traditional LASIK surgery with Intralase.
* The ability to predetermine and accurately apply flap diameter, thickness, and location with the help of computers,
* Thinner sections, which allow for LASIK to be applied to patients with thin corneas and patients with high refractive errors,
* Decreased risk of dry eye as corneal nerves are less likely to be damaged,
* A vertical circumferential section, which allows for a better and more stable adhesion after the surgery; this will also decrease the risk of epithelial ingrowth under the flap,
* Sharp flap edges, which allow for better adhesion of the flap, decreasing the risk of slipping and wrinkling, and accelerating healing,
* Can be used for patients with too flat or too steep corneas, or with a narrow space between the eyelids (which increases risks associated with the microkeratome procedure).
IMAGES OF INTRALASE OPERATION
The LASIK method is based on removing the upper surface of the cornea by cutting a thin layer and opening it like a small flap,and correcting any refraction errors with “excimer laser” on the exposed cornea surface.
Excimer Laser is now used in medical practice to correct refraction errors such as myopia, hyperopia, and astigmatism. Millions of people have been treated with this method since the early 1980s. More than 30 million people have been treated with this method worldwide since it has become available. I myself have performed over 35,000 LASIK surgeries.
This procedure includes the removal of the thin tissue that covers the cornea called as ‘the epithelium’ and applying excimer laser to the underlying tissue. Since there is no flap creation as in LASIK, the cornea is covered with a protective contact lens. This method is generally preferred for patients that cannot undergo LASIK – due to insufficient cornea thickness – or microkeratome – due to insufficient distance between the eyelids. Obtaining a clear vision takes 3-4 weeks, which is significantly longer than LASIK. The first 2-4 postoperative days are painful due to epithelial healing.
While the LASIK method employs lifting the created corneal flap, PRK removes the epithelium of the cornea to apply Excimer Laser.
PERSONALIZED LASER REFRACTIVE SURGERY
Each person has a unique eye structure and vision. Wavefront, Q-value and Corneal Topography technologies make it possible to personalize LASIK surgery.
Wavefront is a personalized treatment method that aims to increase the quality of vision even more than classical LASIK treatment. The wavefront analyzer sends a beam of light to the eye which is then refracted from the retina. The obtained data is used to plan the operation. This method scans the refractive media of the eye and determines any optic aberrations – other than myopia, hyperopia, and astigmatism – to create a unique treatment map. LASIK surgery follows this map to correct the patient’s vision.
The aberrations may cause decreased visual acuity, decreased night vision, and glare. Sculpting the cornea to correct all optical aberrations of the eye will enhance visual definition and contrast sensitivity, providing an improved vision. Thus, the person can make the best use of their visual potential. The wavefront technique can also be successfully applied to patients with irregular astigmatism and in patients who have previously undergone refractive surgery without achieving the desired visual quality.
This method includes applying laser refractive surgery with the help of corneal topography in patients with irregular corneas or a history of flap decentralization. Q-Value-Guided LASIK: This treatment method aims to preserve the aspheric structure of the cornea as much as possible.
Like PRK, this method can be preferred for patients whose corneal thickness is not sufficient for LASIK. It is similar to PRK, but this method does not remove the epithelial tissue but lifts it like a flap with the help of diluted alcohol, and places it back on the cornea after laser application. As the epithelium is preserved, recovery is less painful compared to PRK, but clear vision is obtained significantly later than LASIK.
INTACS (CORNEAL INSERTS)
Intacs can be used in keratoconus patients with myopia of 1-4 diopters whose cornea is not suitable for LASIK. The groove that the implant will be placed in can be created mechanically with a scalpel, or with Intralase. After Intacs are placed inside the cornea, they stretch the cornea to reduce the steepness caused by keratoconus. Corneal implant placement has recently become an alternative to cornea transplant, which was the only treatment method for advanced keratoconus. This treatment improves keratoconus patients’ vision without glasses or contact lenses.
Although there are three different types of corneal inserts (Intacs, Ferrara ring, Keraring), Intacs are the most commonly used type in clinical practice. Unlike LASIK, the purpose of this treatment is not to eliminate the visual defect, but to decrease it.
These inserts are not visible without close inspection, nor are they noticeable to the patient like contact lenses. The inserts can be easily removed at any time and do not affect vision since they are placed outside the visible area. This surgery does not prevent the patient from undergoing other eye surgeries like cataract surgery.
The ideal implant is chosen among various thicknesses as per the severity of keratoconus. The groove to which the implant will be placed can be formed in two different ways:
(1) Mechanically; A special instrument with two parallel cylindrical blades is placed on the cornea which forms grooves as it moves with the help of its mechanism.
(2) Intralase; Since the groove is formed with computer-controlled laser pulses, the depth and diameter of the grooves are more accurate, and the procedure takes a shorter amount of time, which improves treatment outcomes. The risk of complications is lower. Approximately 20% of all keratoconus patients require a cornea transplant. A cornea transplant is inevitable for advanced-stage patients. Intacs are a very safe and low-risk method compared to keratoplasty. Intacs eliminate or at least delay the requirement of a cornea transplant in keratoconus patients.
This method is an alternative to PRK and LASEK for patients with thin corneas. It employs an instrument called ‘epikeratome’ that replaces diluted alcohol to remove the epithelium. It is considerably less painful than PRK and LASEK, and has a shorter recovery time.
PHAKIC INTRAOCULAR LENSES
This method includes the placement of a synthetic intraocular lens inside the eye in order to correct the refractive errors without first removing the patient’s anatomic lens. This method is often preferred in the treatment of very high refractive errors. This method can correct myopia of 1 to 25 Diopters, hyperopia of 1 to 13 Diopters, and myopic and hyperopic astigmatism of 1 to 6. Phakic intraocular lenses make it is possible for severely myopic and hyperopic patients whose eye structure is not suitable for LASIK treatment (for example, due to a thin cornea) to see without glasses or contact lenses.
Phakic intraocular lens (IOL) surgery can be applied to patients aged 18 and older who do not have glaucoma (ocular hypertension), retinopathy or cataracts. The final decision on whether this treatment is suitable for your eye structure is determined by detailed examinations including the assessment of your cornea tissue with specific examinations, as well as determining refraction and pupil diameter in the dark.
Phakic IOL surgery takes approximately 10 minutes for one eye, and the patient will not feel anything as the procedure is performed under anesthesia. Both eyes can be operated with two separate surgeries that will be at least 5-6 days apart, and the operated eye will remain closed with eye dressing for 1 day. After the dressing is removed the following day, the patient will have a vision clear enough to return to their normal life without glasses or contact lenses. The vision will completely recover in 4 to 6 weeks. The intraocular lens is transparent and made from a material that is compatible with your eye, and can last a lifetime without any issues. It is invisible from the outside and will not be felt by the patient.
LASIK TREATMENT PROCESS
- Step: Examinations
Corneal topography creates the topographic map of the corneal layer of the eye in detail. Corneal thickness is measured with corneal pachymetry. Corneal thickness is as important in determining the ideal treatment method as the refractive error.
- Step: Physical Examination
The physical examination determines visual acuity, refractive error, and the other required measurements. The physician performs a biomicroscopic examination and measures intraocular pressure.
Diseases such as diabetes, goiter, rheumatic diseases, and high blood pressure are investigated in detail. Wavefront or Topography examinations can also be used if needed.
- Step: Eyedrop test
The physician will apply a drop to the patient’s eye which will widen the pupils. After waiting 15-20 minutes, refractive errors are measured again, and the fundus of the eye (eyeground) is examined in detail (retina, blood vessels, and nerves). If the retina contains thin regions, tears, or punctures, these regions are treated with argon laser to protect the retina. Argon laser application will delay the excimer laser treatment for 3 weeks, but will not interfere with the treatment and will provide a safer application.
After the examinations, the physician decides on the ideal treatment method for the patient. LASIK treatment may not be performed on the same day as the pupils will be dilated and need some time to return to their normal state. The patient will be provided with an appointment for the next day at the earliest.
To the attention of LASIK treatment patients
You are allowed to eat and drink on the day of the operation.
However, the patient must NOT:
- Wear eye makeup,
- Use perfume, or
- Use blood thinners.
The patient will be asked to lie on their back when they enter the treatment room. The eye is cleaned with an antiseptic solution and covered with a sterile dressing, then the eyelids are separated with a special medical device to prevent blinking during the treatment. LASIK treatment takes about 4-5 minutes for each eye, during which the patient will not feel any pain. The patient leaves the treatment room without the eye being dressed.
First 24 hours after treatment
After LASIK treatment, the patient will undergo a postoperative follow-up examination, after which they can leave the hospital. It is normal to have blurred vision and 5-6 hours of stinging, burning, and watering in the eyes on the first day. Follow your physician’s directions and recommendations in using medication. If you develop a headache after LASIK treatment, you can take a painkiller that does NOT have blood-thinning properties. Do not drive or work on the day of the operation. Avoid a dusty environment, do not rub, itch, or touch the operated eye, or wash your face or take a shower during the first 24 hours. Be careful not to let soap into the operated eye for a few days after the operation. You can go back to your normal life the day after the operation. If the physician determines a wrinkle on the surface of the eye or a reaction under the flap during the follow-up visit on the day after the operation, it may be necessary to remove and wash under the flap.